Supplements containing saw palmetto may support hair growth and prostate health, among other potential benefits. But some people, including those who may be pregnant, should avoid it.
Saw palmetto (Serenoa repens), a type of palm native to the southeastern United States, is commonly used in supplements to improve prostate health, balance hormone levels, and prevent hair loss in men.
Though more research is needed, it may have health benefits, including decreased inflammation and improved urinary function.
Here are five promising benefits and uses of saw palmetto, along with some key risks and side effects.
1. May prevent hair loss
Hair loss is a common condition caused by various factors, including genetics, certain medical conditions, hormone changes, and medications such as stimulants and blood thinners.
People often use saw palmetto to balance hormone levels and reduce hair loss.
Saw palmetto may help block the activity of 5-alpha reductase, an enzyme that converts testosterone into dihydrotestosterone (DHT), a sex hormone linked to hair loss. Saw palmetto may also prevent hair loss by reducing the uptake of DHT in your hair follicles, which decreases DHT’s ability to bind to specific hormone receptors.
The same review also found that oral and topical supplements containing saw palmetto improved hair quality by 60%, raised total hair count by 27%, and increased hair density in 83% of people with hair loss.
According to a 16-week 2023 study in people with androgenic alopecia who took a specifically formulated saw palmetto oil supplement, saw palmetto resulted in decreased hair fall, improved growth, and improved scalp appearance, compared to a placebo.
Even though some study results suggest that saw palmetto may benefit hair growth, more research is still needed.
2. May improve urinary tract function
Saw palmetto may improve urinary symptoms associated with benign prostate hyperplasia (BPH), a condition that causes an enlargement of the prostate gland and results in decreased urine flow. However, more research is still needed.
In one small 12-week study, participants with BPH who took 1,000 mg daily of saw palmetto oil enriched with beta-sitosterol, a compound found naturally in many plants, experienced significant improvements in BPH symptoms compared with those who took unenriched saw palmetto oil.
A 24-week study of 354 participants found that taking 320 mg of saw palmetto decreased symptoms of BPH and improved urinary flow, quality of life, and sexual function compared with a placebo.
However, a 2021 review of 27 studies concluded that saw palmetto had no significant impact on lower urinary tract symptoms when used alone.
More research is needed to determine whether this supplement aids urinary tract function in the general population, including in those with and without prostate issues.
If you have urinary symptoms, it is best to talk with a healthcare professional before taking saw palmetto or other natural remedies, as these symptoms may result from underlying health conditions that require treatment.
3. May support prostate health
The prostate is a small gland located between the bladder and the penis. It’s responsible for maintaining sperm health.
Research suggests that saw palmetto can support prostate health and help prevent issues such as BPH and prostate cancer. Additional studies also indicate this supplement may reduce BPH-related urinary symptoms and inflammation.
A 15-year study of 30 participants with BPH concluded that taking 320 mg of saw palmetto extract daily may help prevent the progression of BPH.
Yet some studies don’t associate saw palmetto with improvements in prostate health or BPH symptoms.
For this reason, further high quality research is needed.
4. May decrease inflammation
Some research in animals suggests that saw palmetto has anti-inflammatory properties, which may help treat certain conditions.
For example, one 2015 study in mice with enlarged prostates observed that saw palmetto extract decreased swelling and several markers of inflammation, including interleukin 6 (IL-6).
Another 2015 study in rats with BPH found that saw palmetto decreased inflammation and improved antioxidant status.
A 2019 review of research suggests that saw palmetto extract may reduce inflammation in the prostate.
Although these results are promising, human studies are lacking. The National Center for Complementary and Integrative Health (NICCH) notes that there isn’t enough research to support the potential benefits of saw palmetto oil for any condition.
5. May help regulate testosterone levels
People looking to boost their testosterone levels naturally often use saw palmetto oil.
Testosterone levels affect several aspects of health, including:
- body composition
- sex drive
- mood
- brain function
Testosterone levels decline with age, and some research suggests that low levels contribute to health conditions such as heart disease.
Saw palmetto may work by decreasing the activity of 5-alpha reductase, an enzyme responsible for converting testosterone to DHT, to help preserve testosterone levels.
According to a 2020 review, saw palmetto may help block the uptake of DHT and decrease its ability to bind to androgen receptors by nearly 50%. This may help regulate testosterone levels.
One older 14-day study also noted that taking 1,200 mg per day of Resettin, a supplement made with saw palmetto and astaxanthin, a type of antioxidant found in algae, increased serum testosterone levels by 38% compared with a placebo.
However, additional studies are needed to support the use and effectiveness of saw palmetto and other natural remedies for regulating testosterone levels.
How does saw palmetto work?
The active compounds in saw palmetto may help block the activity of 5-alpha reductase, an enzyme responsible for converting testosterone to DHT.
This process may help maintain testosterone levels as you get older. Improved testosterone levels may lead to improvements in body composition, libido, and mood.
Because DHT is also involved in the enlargement of the prostate gland, decreasing your levels of DHT by using saw palmetto may also improve prostate health and BPH.
Saw palmetto may also support hair health, as DHT regulates hair growth and may contribute to hair loss and balding, according to test tube and animal studies.
However, the research is mixed, and it’s unclear whether saw palmetto is effective for any of these conditions.
Forms and dosage recommendations
Saw palmetto is widely available as a supplement in capsule, soft gel, and tablet form. Manufacturers may combine it with other ingredients that potentially enhance prostate health, such as pumpkin seed extract.
Though less common, you may also find it in other forms, including:
- ground
- dried
- liquid extract
- powdered tea
Most research uses saw palmetto in dosages of 320 mg daily, often divided into 2 doses.
Some experts recommend taking the supplement with food, which may minimize digestive issues and prevent adverse effects.
It’s best to purchase supplements from brands that submit their products for independent quality testing to ensure the supplements contain the correct ingredients in the correct doses.
Read more about choosing high quality vitamins and supplements.
Potential side effects of saw palmetto
Saw palmetto is generally considered safe and has very few side effects.
Some commonly reported side effects include:
- headache
- dizziness
- nausea
- constipation
However, people who are pregnant or nursing should avoid this supplement, as there is limited research on its safety and long-term effects.
Because it may alter hormone levels, saw palmetto may likewise be unsuitable for those taking hormone replacement therapy or hormonal contraceptives. However, more research is needed to evaluate its potential effects.
Be sure to consult a healthcare professional before trying saw palmetto, especially if you have underlying health conditions, are taking certain medications, or are pregnant or nursing.
The bottom line
Saw palmetto is a species of palm used to produce a supplement packed with potential health benefits.
Promising research suggests that saw palmetto may help increase testosterone levels, improve prostate health, reduce inflammation, prevent hair loss, and enhance urinary tract function.
However, some studies have turned up mixed results. Additional large-scale human research is needed to understand how saw palmetto affects health.
Just one thing
Try this today: While herbal supplements such as saw palmetto may be beneficial, numerous other micronutrients are also necessary for hair growth. Check out our article for a few of the best vitamins and minerals that may prevent hair loss.